The exemplary embodiments of the invention relate to a cell recovery procedure on a single modem board that supports a multi-cell configuration using a multi-core processor with a single SMP partition that contains all the processor cores. While the invention is particularly directed to the art of wireless telecommunications, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications.
By way of background, LTE (Long Term Evolution) is a rapidly evolving 3GPP project that aims to improve the UMTS (Universal Mobile Telecommunications System) mobile phone standard to cope with future communication network demands. LTE improves wireless network efficiency and bandwidth, lower costs and enhance services experience. Specifically, LTE makes use of new spectrum opportunities and offer better integration with other open standards. LTE generally includes an LTE RAN (Radio Access Network) (also known as E-UTRAN) along with an EPS (Evolved Packet System, also called Evolved Packet Core).
Communication systems are generally split into two primary functions: data plane functions and control plane functions. In previous LTE products, at least two processors were used on the modem board: one to support the control plane functions (non-real time, e.g., Operations, Administration, and Management (or OA&M), and call processing management-related functionalities), and another to terminate and support the data plane functions (real time, e.g., LTE Layer 2 processing). Both the control and data planes used different operating system (OS) instances, such as Linux for the control plane and a real-time OS such as vXWorks (made and sold by Wind River Systems of Alameda, Calif.) for the data plane core. Typically, one modem board supported one sector or cell. So to support multi-cell (e.g., three cells or six cells) configurations, it would be necessary to provide as many modem boards as the number of cells.
As an improvement, a multi-core processor may be used on a modem board in an LTE wireless base station. In that case, an operating system such as SMP Linux with PREEMPT RT patch runs on one SMP (symmetric multiprocessing) partition that contains all eight cores. In this configuration the control plane (non-real time threads/processes) and the data plane (real time threads/processes) share the same operating system instances even though they are bound to run on different cores.
Since the modem board supports multiple cells and sectors, cell recovery can become complex. In the previous implementation (i.e., using one modem board to support each cell), the cell recovery procedure following a software crash was simple. In that case, the entire modem board was rebooted. The modem board was then restarted with all of the hardware and software components initialized properly, ready for the master OA&M-C running on the controller board to reconfigure the cell on the modem board.
With the new architecture rebooting the modem board to recover or rescue a cell is no longer a viable option, as it will cause the control plane and the remaining active cells supported by the modem board to reboot as well. High availability is a critical service provider requirement and bringing down all of the cells when just one cell has to be restarted or reconfigured again after a software crash is not an acceptable option.
Thus, there is a need for a method and system that helps to ensure that any cell crash (i.e., an involuntarily action occurring as a result of a software bug or malfunction) is localized to a single cell. In this regard, the control plane and the remaining cells that are configured on the modem board should remain operational. Further, the operator should be able to choose to take corrective action (i.e., reboot, reconfigure, delete, or create) with regard to a cell on the modem board without impacting the operations of the other configured cells.